Lamp holding tool, lighting device for display device using the same, display device using the same and liquid crystal display device using lighting device for display device

ABSTRACT

A lamp holding apparatus for mounting a lamp to a base member includes a mounting plate having a pair of locking portions protruding to a base side. The locking portion is inserted into a mounting hole provided at the base and capable of being locked to a peripheral edge on its back side. Abutting portions, which protrude to the base side and are capable of abutting the base at the time of mounting, are provided on a bottom surface of the mounting plate that is an opposing surface to the base. The abutting portions are provided at three spots with one of the locking portions interposed therebetween. At the time of mounting, each of the abutting portions abut the base, and the mounting plate is elastically deformed so as to be warped, whereby the locking surface of the locking portion is kept in the state in which it is locked to a peripheral edge of a back side of the mounting hole by its elastic force.

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority from Japanese Patent Application No.2004-347324 filed Nov. 30, 2004, the entire contents of which are herebyincorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a lamp holding apparatus, a lightingdevice for a display device including the lamp holding apparatus, adisplay device including the lighting device, and a liquid crystaldisplay device including a lighting device for a display device.

2. Background of the Invention

Since a liquid crystal panel used in a liquid crystal display device of,for example, a liquid crystal television or the like is notself-luminous, it requires a separate backlight device as an externallamp. The backlight device is installed at a back side of the liquidcrystal panel, and generally includes a base made of a metal with asurface on a liquid crystal panel side opened, a number of cold-cathodetubes accommodated in the base as lamps, and a number of optical members(diffusion sheet and the like) arranged on the opening portion of thebase and efficiently releasing light emitted by the cold-cathode tubesto the liquid crystal panel side, and includes lamp clips for holdingthe cold-cathode tubes, which have a slim elongated tube shape, withrespect to the base.

As one example of the lamp clip described above, the lamp clip disclosedin Japanese Patent Laid-Open No. 2001-210126 is known. This lamp clip ismade of a synthetic resin, and includes a mounting plate arranged alongan inner surface of a base, a locking portion which protrudes to a baseside from the mounting plate and is inserted into a mounting hole of thebase and is lockable to its peripheral edge, a lamp holding portionwhich protrudes to an opposite side from the locking portion from themounting plate and is capable of holding a peripheral surface of acold-cathode tube so as to surround it, and a pin which protrudes in thesame direction as the lamp holding portion from the mounting plate. Thepin protrudes to a larger extent than the lamp holding portion, andtherefore, when the lamp clip is mounted to the base, an operatorperforms a mounting operation by gripping the pin.

Incidentally, the production of lamp clips can result in some variationin size that, due to an error in manufacture, cannot be avoided. Inconsideration of the error, the distance between the opposing surface tothe base in the mounting plate and the opposing surface to the base inthe locking projection is set to be a little larger than the platethickness of the base, and therefore, it is possible that the mountedlamp clips rattle with respect to the base due to the clearance.

One option to reduce rattling is to include a locking portion. Thelocking portion is arranged to protrude at the mounting plate and thelocking portion is inserted into a mounting hole formed in the base. Thelocking portion is designed to supplement an elastic force by furtherproviding a projection facing to the base side to protrude at themounting plate, and by elastically deforming the projection to compressthe projection.

However, the elastic rebound force obtained by compression of theprojection is extremely small, and therefore, even if such a projectionis formed on the lamp holding apparatus, rattling of the lamp holdingapparatus with respect to the base member cannot be sufficientlyabsorbed and prevented.

SUMMARY OF THE INVENTION

In order to overcome the problems described above, preferred embodimentsof the present invention provide a lamp holding apparatus that iscapable of preventing rattling with respect to the base member.

A lamp holding apparatus according to a preferred embodiment of thepresent invention is provided for mounting a lamp to a base member andincludes a mounting plate applied to the base member, and a lockingportion protruding to a base member side from the mounting plate andinserted into a mounting hole provided in the base member so as to belockable to a peripheral edge of its back side, and includes an abuttingportion which protrudes to the base member side and is capable ofabutting the base member at a time of mounting, the abutting memberbeing provided on the mounting plate on a surface that opposes the basemember, in at least two spots with the locking portion therebetween, orin at least one spot between a plurality of locking portions.

With such a unique construction, when the lamp holding apparatus ismounted to the base member, the locking portion is inserted into themounting hole and locked to the peripheral edge of its back side, andthe abutting portion protruding from the mounting plate is caused toabut against the base member. In the lamp holding apparatus, a variationinevitably occurs in the size of each product due to an error inmanufacture, and this causes the possibility that a clearance inaccordance with a variation occurs between the mounting plate and thebase member in the mounted state. However, according to preferredembodiments of the present invention, even if the above describedclearance occurs, the abutting portion abuts the base member, wherebythe mounting plate between the abutting portions elastically deforms toeliminate the clearance between the locking portion and the mountinghole.

Other features, elements, steps, characteristics and advantages of thepresent invention will become more apparent from the following detaileddescription of preferred embodiments of the present invention withreference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view showing an outline of a liquidcrystal display according to a preferred embodiment of the presentinvention.

FIG. 2 is a sectional view showing an outline of the liquid crystaldisplay device.

FIG. 3 is a sectional front view showing a state before a lamp clip ismounted to a base.

FIG. 4 is a plan view of the lamp clip.

FIG. 5 is a bottom view of the lamp clip.

FIG. 6 is a partial plan view of a base.

FIG. 7 is a sectional front view showing a state during mounting of thelamp clip to the base.

FIG. 8 is a sectional front view showing a state in which the lamp clipis mounted to the base.

FIG. 9 is a bottom view showing a lamp clip according to anotherpreferred embodiment of the present invention.

FIG. 10 is a bottom view showing a lamp clip according to anotherpreferred embodiment of the present invention.

FIG. 11A is a bottom view showing a lamp clip according to anotherpreferred embodiment of the present invention.

FIG. 11B is a sectional front view showing a state in which the lampclip according to another preferred embodiment of the present inventionis mounted to a base.

FIG. 12A is a bottom view showing a lamp clip according to anotherpreferred embodiment of the present invention.

FIG. 12B is a sectional front view showing a state in which the lampclip according to another preferred embodiment of the present inventionis mounted to a base.

FIG. 13A is a bottom view showing a lamp clip according to anotherpreferred embodiment of the present invention.

FIG. 13B is a sectional front view showing a state in which the lampclip according to another preferred embodiment of the present inventionis mounted to a base.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

A preferred embodiment of the present invention will be described withreference to FIGS. 1 to 8. In this preferred embodiment, a lamp clip 20used in a backlight device 12 of a liquid crystal display device 10 willbe shown as an example. A vertical direction will be described with eachof the drawings as the reference and a lateral direction will bedescribed with FIG. 3 as the reference hereinafter.

First, an outline of the entire liquid crystal display device 10 will bedescribed. The liquid crystal display device 10 preferably generallyincludes a liquid crystal panel 11 having a substantially rectangularshape, and the backlight device 12 that is an external light source, andthe liquid crystal panel 11 and the backlight device 12 are integrallyheld by a bezel 13 or the like, as shown in FIGS. 1 and 2. The liquidcrystal panel 11 that is a display panel has a construction in which apair of glass sheets are bonded to each other with a predetermined gaptherebetween, and liquid crystal is sealed between both the glasssheets. One of the glass sheets is provided with switching elements (forexample, TFT elements) connected to source wiring and gate wiring whichare substantially perpendicular to each other and the other glass sheetis provided with pixel electrodes of R, G and B, respectively, arrangedin a matrix configuration.

Next, the backlight device 12 will be described. The backlight device 12preferably includes a metal base 14 preferably having a substantiallyrectangular box shaped configuration with a top surface side opened, aplurality of optical members 15 mounted to cover the opening of the base14 (a diffusion plate, a diffusion sheet, a lens sheet and an opticalsheet in the sequence from the lower side in the drawing), a frame 16for holding these optical members 15 on the base 14, cold-cathode tubes17 that are lamps accommodated in the base 14, a rubber (for example,silicon rubber) holder 18 for holding both end portions of thecold-cathode tubes 17, lamp holders 19 that collectively cover thecold-cathode tube 17 group and the holder 18 group, and lamp clips 20for holding intermediate portions except for both end portions in thecold-cathode tubes 17.

The cold-cathode tube 17 preferably has a slim elongated shape, and anumber of cold-cathode tubes 17 are accommodated in the base 14 in thestate in which their length direction (axial direction) coincides withthe long side direction of the base 14 and a plurality of thecold-cathode tubes 17 are arranged substantially parallel to each other.The outside diameter dimension of the cold-cathode tube 17 is preferablyabout 3 mm to about 4 mm, for example, but it sometimes increases anddecreases in the tolerance range due to an error in manufacture or asdesired.

The lamp clip 20, which is preferably made of a synthetic resin (forexample, polycarbonate), includes a mounting plate 21 applied to a wallsurface of a bottom portion of the base 14. Lamp clip 20 also includeslocking portions 22, lamp holding portions 23, a pin 24 and the like. Aplurality of the lamp clips 20 are mounted to the base 14 so as to beable to hold each of the cold-cathode tubes 17 preferably at two spotsor three spots differing in the length direction. The surface of theentire lamp clip 20 is preferably colored to be white, for example, soas to make it difficult to shield and reflect the light emitted from thecold-cathode tube 17.

The mounting plate 21 preferably has a substantially rectangular slimelongated shape extending along the short side direction of the base 14(direction that is substantially perpendicular to the length directionof the cold-tube cathode 17). The locking portion 22 for fixing the lampclip 20 to the base 14 is provided at a bottom surface 21 a (theopposing surface to the base 14, the surface attached to base 14) of themounting plate 21 so as to protrude downward (base 14 side) as shown inFIG. 3. A pair of locking portions 22 are provided at the mounting plate21, and both the locking portions 22 are preferably arranged at thelocations spaced substantially equidistantly from both end positions ofthe mounting plate 21 with respect to the long side direction of themounting plate 21, and are both arranged at central positions withrespect to the short side direction of the mounting plate 21, as shownin FIGS. 3 and 5.

The locking portion 22 preferably includes a base portion 25 arranged tohang from the bottom surface 21 a of the mounting plate 21, and a pairof elastic locking pieces 26 extending diagonally upward from a tip endportion of the base portion 25 (to the mounting plate 21 side whileseparating from the base portion 25). The base portion 25 preferably hasa substantially rectangular elongated slim shape extending along theshort side direction of the mounting plate 21 (FIG. 5). The elasticlocking pieces 26 are each preferably has an open sided shape connectedto both side surfaces at the side of a long side in the tip end portionof the base portion 25, and are elastically deformable along thedirection to contact and separate from the base portion 25 with theirconnecting portions as the support points. The locking portion 22 iscapable of being inserted into each mounting hole 14 a which is providedat the corresponding position in the base 14 so as to penetrate throughit. Further, a step portion formed at the tip end portion in the elasticlocking piece 26 is capable of being locked to the peripheral edge atthe back side in the mounting hole 14 a, and this becomes a lockingsurface 26 a that is locked to the base 14 (FIG. 8).

The locking surface 26 a of the elastic locking piece 26 and the bottomsurface 21 a of the mounting plate 21 are arranged to oppose each otherwhen they are separated from each other as shown in FIG. 3, and adistance between both the surfaces 21 a and 26 a is preferably a littlelarger than the plate thickness dimension of the base 14 inconsideration of an error in manufacture of the lamp clip 20. In detail,the distance between both the surfaces 21 a and 26 a increases anddecreases within the tolerance range due to an error in manufacture ofthe lamp clip 20, but by setting it as described above, the distancebetween the surfaces 21 a and 26 a becomes about the same as the platethickness dimension of the base 14. Thus, mounting to the base 14 isallowed even when the distance between both the surfaces 21 a and 26 ais at the minimum value of the tolerance range.

On the top surface of the mounting plate 21 (opposing surface to thecold-cathode tube 17, a surface at the opening side of the base 14), alamp holding portion 23 for holding the intermediate portion of thecold-cathode tube 17 except for both end portions in the lengthdirection is arranged to protrude upward. Three lamp holding portions 23in total, for example, are preferably provided at positions which arespaced substantially equidistantly from both end positions in the longside direction of the mounting plate 21 (in detail, positions near anoutside from the locking portions 22) and at a substantially centralposition, as shown in FIGS. 3 and 4. Each of the lamp holding portions23 is preferably located at a central position with respect to the shortside direction of the mounting plate 21.

The lamp holding portion 23 is capable of surrounding the peripheralsurface of the cold-cathode tube 17 as a whole as shown in FIG. 2, andpreferably has a bottomed annular shape, which is opened upward to allowattachment and detachment of the cold-cathode tube 17. In detail, asshown in FIG. 3, the lamp holding portion 23 includes a pair of armportions 27 connected at root portions of each other, and has theconstruction in which both arm portions 27 are connected to a connectingportion 28 vertically extending from the top surface of the mountingplate 21 so as to be able to hold the cold-cathode tube 17 at a positionraised by a predetermined height from the mounting plate 21. Both thearm portions 27 preferably have open-sided shapes in which root portionsprotrude outside along a substantially horizontal direction (oppositeside from each other), and thereafter, extending diagonally upward to aninside (in a direction close to each other), and are symmetrical inshape with each other. In both the arm portions 27, the space betweenthe tip end portions is a space which is narrower than the minimumoutside diameter dimension of the tolerance range in the cold-cathodetube 17. Through this clearance, attachment and detachment of thecold-cathode tube 17 are allowed, and both the arm portions 27 arecapable of elastically deforming to open (elastically deformable whileexpanding the clearance between the tip end portions) with attachmentand detachment.

Guide portions 29 protruding diagonally upward to an outside andseparate from each other are respectively provided at outer surfaces ofthe tip end portions of both the arm portions 27. The inner surfaces ofboth the guide portions 29 define guide surfaces 29 a, each preferablyhaving a tapering shape, and a distance between both the guide surfaces29 a becomes gradually large as they extend upward. Namely, acceptancewidth for the cold-cathode tube 17 in the lamp holding portion 23gradually increases toward a front side in the mounting direction, andtherefore, mounting of the cold-cathode tube 17 is facilitated. Both theguide surfaces 29 a are formed to define a substantially right anglewith each other.

Inner peripheral surfaces of both the arm portions 27 include threegentle arc surfaces 30 and 31 which are formed at a root portion and inthe vicinity of both tip end portions, and when virtual tangential linesof the respective arc surfaces 30 and 31 are connected, an equilateraltriangle is formed. The respective arc surfaces 30 and 31 are preferablygentler than a peripheral surface of the cold-cathode tube 17, and inother words, curvatures of the respective arc surfaces 30 and 31 arepreferably smaller than the curvature of the peripheral surface of thecold-cathode tube 17. Among the respective arc surfaces 30 and 31, boththe arc surfaces 30 at the tip end side of both the arm portions 27, thetip end portions are made point contact portions 32, which arepoint-contactable to the cold-cathode tube 17 with respect to thecircumferential direction. As for the arc surface 31 at the root side,its central portion is made a point contact portion 33, which ispoint-contactable to the cold-cathode tube 17 with respect to thecircumferential direction. Both the point contact portions 32 at the tipend sides of both the arm portions 27 make it possible to press thecold-cathode tube 17 from above or from the removing direction ofcold-cathode tube 17. The arc surface 31 of the root portions of boththe arm portions 27 have a configuration such that a central portion inits circumferential direction is the deepest, and therefore, it is madepossible to guide the cold-cathode tube 17 to be mounted to the centralposition. In the mounting state, each of the point contact portions 32and 33 is located at the vertex point of the isosceles triangle or theequilateral triangle though it differs depending on the thickness of thecold-cathode tube 17 (see FIG. 8). A connecting portion of the arcsurface 30 at the tip end side in the arm portion 27 and the abovedescribed guide surface 29 a preferably has a substantially round shape.

In the lamp holding portion 23, both the arm portions 27 elasticallydeform to open a little in the mounting state and the respective pointcontact portions 32 and 33 are arranged to be able to contact firmly tothe peripheral surface of the cold-cathode tube 17, which allows forholding it without rattling, even when the thickness of the cold-cathodetube 17 to be mounted is at the minimum value in the tolerance range.

Recessed portions 34 are preferably provided at the inner peripheralsurfaces (opposing surfaces to the cold-cathode tube 17) in both the armportions 27. In detail, the recessed portion 34 is placed between theadjacent arc surfaces 30 and 31 (between the tip end portion and theroot portion of the arm portion 27, namely, the connecting region withrespect to the connecting portion 28) of the inner peripheral surface ofthe arm portion 27, and is formed into an arc shape more acutely thanthe respective arc surfaces 30 and 31 (with a relatively largecurvature, with a relatively small radius of curvature). The recessedportion 34 extends over the entire width of the arm portion 27, and ispreferably deeper toward a central portion in the circumferentialdirection. An outer peripheral surface of the arm portion 27 at therecessed portion 34 is provided (the surface at the opposite side fromthe opposing surface to the cold-cathode tube 17) is formed to bulgeoutwardly by the amount by which the arm portion 27 is recessed by therecessed portion 34. In other words, in the direction separate from thecold-cathode tube 17, whereby the arm portion 27 is formed to havesubstantially uniform thickness over substantially the entire length.The arm portion 27 is allowed to bend to deform to open with the regionat the root side of the portion where the recessed portion 34 isprovided as the support point, namely, so that the tip end portiondisplaces in the direction separate from the peripheral surface of thecold-cathode tube 17. Thereby, opposed to a situation where the recessedpart is not provided, the operational force required to deform the armportion 27 to open is reduced. Further, in the arm portion 27, a totalsurface distance (arm length) from the root portion to the tip endportion (being a free) end becomes large as a result of the portionprovided with the recessed portion 34 bulging outwardly.

On the top surface of the mounting plate 21, a pin 24 capable ofabutting the optical member 15 is arranged to protrude upward (the samedirection as the lamp holding portion 23) as shown in FIG. 3. The pin 24preferably has a substantially conical shape (tapering shape) with arounded tip end, so as to be able to support the optical member 15 bythe tip end portion. The height dimension of the pin 24 is larger thanthe lamp holding portion 23, and is set at, for example, about threetimes as large as the lamp holding portion 23, and therefore, when thelamp clip 20 is mounted to the base 14, an operator can perform theoperation by gripping the pin 24. The pin 24 is disposed at anintermediate position between the left end lamp holding portion 23 andthe central lamp holding portion 23 and at the position corresponding tothe back side of the locking portion 22 as shown in FIGS. 3 and 4, andis arranged to overlap a part of the locking portion 22 with respect tothe surface direction of the mounting plate 21.

On the bottom surface 21 a (opposing surface to the base 14) of themounting plate 21, abutting portions 35 and 36 are capable of abuttingthe top surface (opposing surface to the mounting plate 21) of the base14 at the time of mounting is arranged to protrude downward (the base 14side) as shown in FIG. 3. The abutting portions 35 and 36 are preferablyprovided at three spots that are in a central position in the long sidedirection in the mounting plate 21, and in the vicinities of both endpositions. The abutting portions 35 and 36 are preferably bow-shaped insectional shape, in other words, a shape having an arc-shaped outersurface which bulges the most at a central portion with respect to thelong side direction of the mounting plate 21. The respective abuttingportions 35 and 36 are located at positions with the locking portions 22therebetween, respectively, and in more detail, the central abuttingportion 35 and the abutting portion 36 at the left end are placed at twopositions with the locking portion 22 at the left side therebetween, andthe central abutting portion 35 and the abutting portion 36 at the rightend are placed at two positions with the locking portion 22 at the rightside therebetween.

Among them, the central abutting portion 35 is also located at thecentral position with respect to the short side direction in themounting plate 21, and preferably has a substantially spherical crownshape capable of being in point contact with the base 14, as shown inFIGS. 3 and 5. The abutting portion 35 is disposed at the intermediateposition between the two locking portions 22 arranged at the left andright in the bottom surface 21 a of the mounting plate 21. The abuttingportion 35 is located on the back side of the lamp holding portion 23 atthe center on the top surface side, and is disposed at the concentricposition with the lamp holding portion 23.

Meanwhile, the abutting portions 36 at both ends each preferably has anembossed shape extending in the short side direction of the mountingplate 21, and are capable of being in line contact with the base 14 withrespect to the same direction. Both the abutting portions 36 have thesame length over the entire width of the mounting plate 21. Both theabutting portions 36 are placed at positions near the ends from the lampholding portions 23 at both ends in the mounting plate 21 and atpositions that are substantially equidistantly spaced from both endpositions of the mounting plate 21. On the bottom surface 21 a of themounting plate 21, the respective abutting portions 35 and 36 arepreferably disposed at substantially symmetrical positions and havesubstantially symmetrical shapes.

A protruding amount of each of the abutting portions 35 and 36 from themounting plate 21 is substantially the same and is set based on an erroroccurring in manufacturing the lamp clip 20. Specifically, due to anerror in manufacture, a variation occurs in the distance between thelocking surface 26 a in the locking portion 22 and the bottom surface 21a of the mounting plate 21 for each product within the tolerance range.The protruding amount of each of the abutting portions 35 and 36 ispreferably slightly larger than a value obtained by subtracting theplate thickness dimension of the base 14 from the maximum value of thetolerance range of the above described distance, i.e., the maximum valueof the clearance occurring between the mounting plate 21 and the base14. Accordingly, the distance between the locking surface 26 a of thelocking portion 22 and the bottom surface 21 a of the mounting plate 21can be any value within the tolerance range when the lamp clip 20 ismounted to the base 14, each of the abutting portions 35 and 36 abutsthe top surface of the base 14, and the mounting plate 21 is elasticallydeformed to be warped with the portions provided with the respectiveabutting portions 35 and 36 as the support points.

As shown in FIGS. 3 and 5, a positioning pin 37 capable of being fittedinto a positioning hole 14 b provided at the base 14 is providedpreferably at a central position in the length direction in the abuttingportion 36 at the left end. As is already described, while the lockingportions 22 and the abutting portions 35 and 36 provided on the backsurface side (the opposing surface side to the base 14) of the lamp clip20 are symmetrically disposed, the lamp holding portions 23 and the pin24 on the front surface side are disposed asymmetrically, and therefore,it may appear that the lamp clip 20 is mistakenly mounted to the base 14in the inverted direction. However, the positioning pin 37 is fittedinto the positioning hole 14 b when the mounting plate 21 is in thecorrect direction when mounting the lamp clip 20 to the base 14, butwhen the mounting plate 21 is in the inverted direction, it ismismatched with the positioning hole 14 b to be able to restrictmounting, and therefore, erroneous mounting can be prevented.

The present preferred embodiment has the above-described uniquestructure, and its operation will be described subsequently. While theliquid crystal panel 11 is manufactured, an assembling operation of thebacklight device 12 is performed. When assembling the backlight device12, the operation of mounting each of the lamp clips 20 to the base 14is performed first.

The pin 24 of the lamp clip 20 is gripped in the state shown in FIG. 3,and while each of the locking portions 22 is matched to each of themounting holes 14 a of the base 14 and the positioning pin 37 is matchedto the positioning hole 14 b, respectively, the mounting plate 21 ispressed against the top surface of the base 14. Then, each of thelocking portions 22 is inserted into each of the corresponding mountingholes 14 a, and the positioning pin 37 is fitted into the positioninghole 14 b. In the process in which the locking portion 22 is insertedinto the mounting hole 14 a, both the elastic locking pieces 26 arelocked to the peripheral edge of the front side of the mounting hole 14a, and thereby, they are elastically deformed to be temporarily close tothe base portion 25.

Then, when the mounting plate 21 is pushed into a predetermined depth,each of the abutting portions 35 and 36 abut the top surface of the base14 as shown in FIG. 7. In this state, both the elastic locking pieces 26remain to be elastically deformed, and the mounting plate 21 is at theposition slightly raised from the base 14 to provide a clearancecorresponding to the protruding amount of the abutting portions 35 and36 between both the base 14 and the mounting plate 21. Then, when themounting plate 21 is further pushed in, the mounting plate 21 isrestricted from displacing in the pushing direction by the base 14 withrespect to the portion where each of the abutting portions 35 and 36 isprovided, and therefore, the portions sandwiched by the restrictingregions are elastically deformed to be warped into the bow shape withthe restricting regions as the support points. When the locking surfaces26 a of both the elastic locking pieces 26 reach the back side of thebase 14, the elastic locking pieces 26 restore as shown in FIG. 8, andthe locking surfaces 26 a are locked to the peripheral edge of the backside of the mounting hole 14 a. At this time, the base 14 is held bybeing sandwiched between the bottom surface 21 a of the mounting plate21 and the locking surface 26 a of the elastic locking piece 26.

In this state, while the portion provided with each of the abuttingportions 35 and 36 of the mounting plate 21 is supported at the positionraised from the base 14, the portions provided with the locking portions22 are elastically deformed to be warped to be close to the base 14side, and therefore, both the locking portions 22 are elastically biasedupward respectively, in the detaching direction. Accordingly, thelocking surface 26 a of each of the elastic locking pieces 26 is kept inclose contact with the peripheral edge of the back side of the mountinghole 14 a in the base 14 by the elastic force of the mounting plate 21,whereby the lamp clip 20 is held in the mounted state to the base 14without rattling up and down. The protruding amount of each of theabutting portions 35 and 36 is preferably larger than the maximum valueof the clearance occurring between the mounting plate 21 and the base 14due to an error in manufacture of the lamp clip 20, and therefore, evenif the distance between the locking surface 26 a of the elastic lockingpiece 26 and the bottom surface 21 a of the mounting plate 21 varies toany value in the tolerance range due to an error occurring duringmanufacturing the lamp clip 20, a warping degree (deformation amount) ofthe mounting plate 21 changes more or less, but each of the abuttingportions 35 and 36 abuts the top surface of the base 14 and the mountingplate 21 elastically deforms to be warped without fail, wherebyoccurrence of rattling to the lamp clip 20 can be reliably preventedirrespective of an error in manufacture.

In this mounted state, both the abutting portions 36 provided at bothends of the mounting plate 21 are in line contact with the top surfaceof the base 14 with respect to the short side direction of the mountingplate 21. Accordingly, the mounting plate 21 is mounted in the statepartially raised from the base 14 by each of the abutting portions 35and 36, but the raised portion of the mounting plate 21 can be preventedfrom rattling (displacing) to be inclined with respect to the short sidedirection by the clearance occurring in a space from the base 14.

After each of the lamp clips 20 is mounted to the base 14, the operationof mounting the cold-cathode tube 17 is subsequently performed. Thecold-cathode tube 17 is held by the lamp clip 20 in the state in whichtwo of them are made one set by attaching the holders 18 at both endportions thereof as shown in FIG. 1.

When the cold-cathode tube 17 is pushed downward while being guided byboth the guide portions 29 of the lamp holding portion 23 and whilebeing guided by both guide portions 29 of the lamp holding portion 23,both the arm portions 27 elastically deform to open with the root sideregions in the portions where the recessed portions 34 are provided asthe support points, and the clearance between both the tip end portionsis widened, whereby entry of the cold-cathode tube 17 is allowed. Then,when the cold-cathode tube 17 passes between the tip end portions ofboth the arm portions 27, both the arm portions 27 close topredetermined positions and each of the point contact portions 32 and 33contacts the peripheral surface of the cold-cathode tube 17, whereby thecold-cathode tube 17 is supported at three points. Although thethickness of the cold-cathode tube 17 increases and decreases within thetolerance range due to an error in manufacture, the recessed portions 34are provided at the opposing surfaces to the cold-cathode tube 17 inboth the arm portions 27, and therefore, an elastic force occurring toboth the arm portion 27 is reduced. Accordingly, the relatively slimcold-cathode tube 17 can be held without rattling, the operation forcerequired for attaching and detaching the relatively thick cold-cathodetube 17 can be reduced, and it is made difficult for the cold-cathodetube 17 to be pushed out to the detaching direction by the elastic forceof the arm portion 27 in the held state, and thus, favorable operabilityand holding performance can be obtained.

After all the cold-cathode tubes 17 are mounted as described above, thelamp holder 19 is mounted, and the optical member 15 and the frame 16are assembled to the base 14 in this sequence, whereby the backlightdevice 12 is provided. By integrally assembling the backlight device 12and the liquid crystal panel 11 using the bezel 13, the liquid crystaldisplay device 10 is provided (see FIG. 1).

As described above, according to this preferred embodiment, the abuttingportions 35 and 36 which protrude to the base 14 side and are capable ofabutting the base 14 at the time of being mounted are providedpreferably at three spots with the respective locking portions 22therebetween, of the bottom surface 21 a that is the opposing surface tothe base 14 in the mounting plate 21, and the protruding amounts are setso that the abutting portions 35 an 36 abut the base 14 to cause warpingin the mounting plate 21 even when a clearance occurs between themounting plate 21 and the base 14 due to an error in manufacture of thelamp clip 20, and therefore, the mounting plate 21 can be caused togenerate an elastic force. Thereby, the locking portion 22 can be keptin the state locked to the peripheral edge of the back side of themounting hole 14 a, whereby rattling can be prevented from occurringbetween the locking portion 22 and the base 14.

A pair of abutting portions 36 are placed at both end positions in thelong side direction in the mounting plate 21 having a substantiallyrectangular shape, and therefore, occurrence of rattling to the mountingplate 21 can be reliably prevented.

Since both the abutting portions 36 are arranged to be capable of beingin line contact with the base 14 with respect to the short sidedirection in the mounting plate 21, occurrence of rattling can beprevented more reliably as compared with the lamp clip in which theabutting portion is caused to be in point contact with the base.

Since the lamp clip 20 is preferably made of a synthetic resin,manufacture is facilitated, and reduction in cost can be achieved.

Since the front surface of the lamp clip 20 is preferably white, ithardly happens that the lamp clip 20 itself shields and reflects thelight emitted from the cold-cathode tube 17 as compared with the casewhere the lamp clip is made black. Thereby, when the cold-cathode tube17 is lit to cause the liquid crystal display device 10 to display, itis difficult for the pin 24 to be visually recognized by a viewer(reduction in luminance or the like is prevented), and therefore,display performance of the liquid crystal display device 10 becomesfavorable.

The present invention is not limited to the preferred embodimentdescribed via the aforementioned description and drawings, and, forexample, the following preferred embodiments and modifications theretoare also included in the technical scope of the present invention.

The above described preferred embodiment shows the case where theabutting portions 36 at both ends in the mounting plate 21 have aconfiguration in line contact with the base 14, but as shown in, forexample, FIG. 9, an abutting portion 36A capable of being in pointcontact with the base 14 may be provided at both ends of the mountingplate 21. Since the abutting portions 36A are disposed at two spotsspaced from each other along the short side direction of the mountingplate 21 respectively at both end portions of the mounting plate 21(four abutting portions 36A in total), the mounting plate 21 can beprevented from rattling to incline with respect to the short sidedirection with respect to the base 14. The abutting portion 36Apreferably has the same shape as the central abutting portion 35 in FIG.9, but it is possible to change each of the shapes.

The above described preferred embodiment shows the case where thecentral abutting portion 35 of the mounting plate 21 has a configurationthat is in point contact with the base 14, but as shown in FIG. 10, forexample, the abutting portion 35B is extended along the short sidedirection of the mounting plate 21 so as to be in line contact with thebase 14 with respect to the same direction. The abutting portion 35Bpreferably has substantially the same shape as the abutting portions 36at both ends in FIG. 10, but may be suitably changeable.

The above described preferred embodiment shows the case preferablyincludes the abutting portions 35 and 36 provided at three spots of themounting plate 21, but as shown in FIG. 11A, for example, only oneabutting portion 35C may be provided at a central position in the longside direction of the mounting plate, between the two locking portions22. In this case, warping can be caused to the mounting plate 21 withthe abutting portion 35C as the support point as shown in FIG. 11B. InFIGS. 11A and 11B, the abutting portion 35C in point contact with thebase 14 is shown, but the abutting portion in the mode in line contactwith the mounting plate 21 with respect to the short side direction maybe adopted.

The above described preferred embodiment shows the lamp clip 20including the two locking portions 22 as an example, but as shown inFIG. 12A, for example, in the lamp clip 20 including only one lockingportion 22D, abutting portions 36D may be respectively provided at twospots with the locking portion 22D therebetween. In this case, as shownin FIG. 12B, the mounting plate 21 can be caused to generate warpingwith both the abutting portions 36D as the support point. In FIGS. 12Aand 12B, the abutting portions 36D are in point contact with the base 14as shown, but the abutting portion in the mode in line contact with themounting plate 21 with respect to the short side direction may beadopted.

In the above described preferred embodiment, the lamp clip 20 includingthe two locking portions 22 is shown as an example, but as shown in FIG.13A, for example, in the lamp clip 20 including three locking portions22E, abutting portions 35E may be provided at two spots each interposedbetween the locking portions 22E, and abutting portions 36E may beprovided at two spots in both end positions in the long side directionof the mounting plate 21. In this case, as shown in FIG. 13B, themounting plate 21 can be caused to generate warping with the abuttingportions 35E and 36E as the support points. In FIGS. 13A and 13B, themode in which the abutting portion 35E is in point contact with the base14 is adopted, but the mode in which the abutting portion 35E is in linecontact with the mounting plate 21 with respect to the short sidedirection may be adopted, or on the other hand the abutting portion 36Eis in point contact with the base 14 may be adopted. Further, it ispossible to omit any of the abutting portions 35E and 36E if only themounting plate 21 can be caused to generate warping.

The present invention is applicable to a lamp clip including four ormore locking portions.

The above described preferred embodiments preferably includes protrudingamounts of the abutting portions 35 and 36 from the mounting plate 21that are larger than the maximum value of the clearance occurringbetween the mounting plate 21 and the base 14, but it is possible to setthe protruding amounts of the abutting portion to be about the same asthe maximum value of the clearance occurring between the mounting plate21 and the base 14, for example. In this case, rattling of the mountingplate 21 can be also prevented by the abutting portion abutting the base14.

The diameter dimension of the abutting portion 35 and the linewidth/line length of the abutting portion 36 or the like can be changed,and the shape of the abutting portions 35 and 36 is changeable withoutbeing limited to the substantially spherical crown shape and theembossed shape described above.

The arrangement positions of the respective abutting portions 35 and 36in the mounting plate 21 can be changed. The arrangement positions donot have to be symmetrical with respect to the back surface side of themounting plate, and may be changed to be asymmetrical.

The mode of the locking portion 22 may be the mode in which the lockingprojections are bulged sidewards from the tip end portion of the baseportion vertically provided from the mounting plate as shown in theprior art, for example, and is changeable in the other respects. Theshape of the mounting plate 21 is not limited to the substantiallyrectangular shape, and the mounting plates having a substantially squareshape and a substantially circular shape are included in the presentinvention.

The above described preferred embodiment preferably uses thecold-cathode tube 17 as a lamp, but modes using the other kinds of lampssuch as a hot-cathode tube, for example, are included in the presentinvention.

The above described preferred embodiment shows the backlight device 12in which the lamp clip 20 is mounted to the substantially box-shapedbase 14, but a mode in which the lamp clip 20 is mounted to the planarbase from which a peripheral wall is removed, for example, is alsoincluded in the present invention.

The above described preferred embodiment includes the lamp clip 20 beingwhite, but the lamp clip 20 may be made colorless and transparent, orsemitransparent and semi-opaque. In doing so, the lamp clip 20 easilytransmits light emitted from the cold-cathode tube 17, and it becomesmore difficult that light is shielded and reflected. Thereby, when thecold-cathode tube 17 is lit to cause the liquid crystal display device10 to display, it is difficult for the pin 24 to be visually recognizedby a viewer (reduction in luminance or the like is prevented), andtherefore, the display performance of the liquid crystal display device10 becomes more favorable. As for the color of the lamp clip 20, thecolors except for the above described color are also included in thepresent invention.

The above described preferred embodiment includes the lamp clip 20 beingmade of a synthetic resin material and polycarbonate, but a syntheticresin material other than this may be used. As the material of the lampclip 20, it is possible to use the other kinds of materials withoutbeing limited to the synthetic resin material. When the synthetic resinmaterial other than polycarbonate and the material other than thesynthetic material are used, the color of the lamp clip 20 can be madeany of white, colorless and transparent, and semitransparent andsemi-opaque.

The present invention is also applicable to the liquid crystal displaydevice using a switching element other than the TFT. The presentinvention is also applicable to the liquid crystal display deviceperforming black and white display other than the liquid crystal displaydevice which provides a color display.

The above described preferred embodiment discloses using the presentinvention with a liquid crystal display device, but the presentinvention is also applicable to the other display devices, for example,devices that use a backlight device other than liquid crystal devices.

While preferred embodiments of the present invention have been describedabove, it is to be understood that variations and modifications will beapparent to those skilled in the art without departing the scope andspirit of the present invention. The scope of the present invention,therefore, is to be determined solely by the following claims.

1. A lighting device for a display device, comprising: a plurality oflamps; and a backlight lamp holding apparatus for mounting saidplurality of lamps to a base member, said backlight lamp holdingapparatus including: a resilient planar mounting plate that is to bemounted to said base member at a first surface of said mounting plateand that includes a plurality of abutting portions protruding from saidfirst surface of said mounting plate; a locking portion having a baseportion protruding from said first surface of said mounting plate, andan elastic locking piece extending from a tip end of said base portion;and a plurality of lamp holding portions that protrude from a secondsurface of said mounting plate and are adapted for holding saidplurality of lamps, respectively; wherein said elastic locking pieceincludes a locking surface that is locked to a peripheral edge ofamounting hole formed through said base member; said plurality ofabutting portions are arranged to abut against a top surface of saidbase member.
 2. A lighting device for a display device as in claim 1,wherein said plurality of abutting portions are spaced away from saidlocking portion in a lateral direction along said first surface of saidmounting plate.
 3. A lighting device for a display device as in claim 1,wherein said plurality of abutting portions are arranged to apply aforce against said base member in a direction that is opposite to aforce applied to said base member by said locking portion.
 4. A lightingdevice for a display device as in claim 1, further comprising analignment pin arranged to ensure proper orientation of said mountingplate relative to said base member, wherein said alignment pin isarranged to extend from said first surface of said mounting plate by adistance that is greater than a distance that said plurality of abuttingportions extend from said first surface of said mounting plate.
 5. Alighting device for a display device as in claim 1, wherein: saidmounting plate has a substantially rectangular shape; and at least twoabutting portions of said plurality of abutting portions are located atrespective end positions of said mounting plate so as to be spaced apartalong a longitudinal direction of said mounting plate.
 6. A lightingdevice for a display device as in claim 1, wherein: said mounting platehas a substantially rectangular shape; and at least one abutting portionof said plurality of abutting portions is arranged to abut against saidbase member at least two positions spaced apart along a short sidedirection of said mounting plate.
 7. A lighting device for a displaydevice as in claim 1, wherein: said mounting plate has a substantiallyrectangular shape; and at least one abutting portion of said pluralityof abutting portions is arranged to be in line contact with said basemember with a contact line along a short side direction of said mountingplate.
 8. A lighting device for a display device as in claim 1, whereinsaid plurality of lamp holding portions are formed of a synthetic resin.9. A lighting device for a display device as in claim 1, wherein saidplurality of lamp holding portions have white surfaces.
 10. A displaydevice, comprising: a lighting device for a display device, as in claim1; and a display panel.
 11. A display device as in claim 10, wherein:said mounting plate has a substantially rectangular shape; and at leasttwo abutting portions of said plurality of abutting portions are locatedat respective end positions of said mounting plate so as to be spacedapart along a longitudinal direction of said mounting plate.
 12. Adisplay device as in claim 10, wherein: said mounting plate has asubstantially rectangular shape; and at least one abutting portion ofsaid plurality of abutting portions is arranged to abut against saidbase member at least two positions spaced apart along a short sidedirection of said mounting plate.
 13. A display device as in claim 10,wherein: said mounting plate has a substantially rectangular shape; andat least one abutting portion of said plurality of abutting portions isarranged to be in line contact with said base member with a contact linealong a short side direction of said mounting plate.
 14. A displaydevice as in claim 10, wherein said display panel is a liquid crystalpanel that including a liquid crystal material.